The Flying Fox deposit is located about 350 km east-southeast of Perth in the Forrestania greenstone belt, which is the southern extension of the Southern Cross greenstone belt, Southern Cross Domain, Youanmi Terrane in the Archean Yilgarn craton of Western Australia. The Forrestania belt trends approximately north–south over a length of 250 km, ranges in width from 5 to 30 km, and is flanked to the east by the Eastern Goldfield Superterrane and to the west by the South West Terrane. Six ultramafic belts are identified in the Forrestania greenstone belt: the Western, Mid-Western, Takashi, Central Fold, Mid-Eastern, and Eastern, with the Flying Fox deposit located in the Western ultramafic belt.

The stratigraphy of the Forrestania greenstone belt consists of: 1) a lower succession of predominantly tholeiite and komatiite metavolcanic sequences intercalated with banded ironformation (BIF), sulfidic chert layers, and localized felsic metasedimentary units; and 2) an uppermost succession of fine-grained clastic sedimentary rocks (pelitic to psammitic schists) with minor BIF horizons, located in the centre of the belt. The stratigraphy has been intruded by granitic rocks which have exploited pre-existing faults, and by east–west trending dolerite dikes.

The Spotted Quoll Nickel sulphide deposit is located at the Forrestania Nickel Operations, 400 km southeast of Perth. Spotted Quoll is located wholly within Mining Lease M77/583. The deposit is hosted within a sequence of sedimentary, ultramafic and mafic rocks within the Western Ultramafic Belt.

The sulphide mineralisation consists of massive to matrix sulphides located in a possible shear zone in metasedimentary rocks overlain by a package of ultramafic and mafic rocks. The deposit belongs to the Archean komatiite hosted nickel type.

Flying Fox is Western Areas first producing underground mine and remains one of the highest grade nickel mines in the world. Production commenced in 2006, and the underground mine now operates at depths of over 1km underground.

The Flying Fox orebody extends from 250m to 1.2km below the surface and includes discrete independent orebodies with possible extensions at depth. The primary stoping method used is ‘top- down’ long-hole stoping using paste-fill to attempt 100% recovery of the high-grade orebody. In the narrower sections of the orebody both modified Avoca with unconsolidated and cemented rock-fill are used.

The Spotted Quoll orebody is open at depth with the mine currently planned to just over 1km below the surface. The primary stoping method is a ‘top-down’ mining method using long-hole open stoping with paste fill. The narrower and shallower areas are mined using top-down narrow vein techniques.

The Cosmic Boy Concentrator has a three stage crushing circuit, followed by a single closed circuit ball mill.

The high-grade nickel ore mined from Forrestania is processed through the Cosmic Boy Concentrator (CBC) and sold into offtake agreements with Jinchuan Group, China’s largest stainless steel producer and BHP Ni West.

The CBC treats the raw nickel and produces a consistent nickel concentrate product grading approximately 14% nickel. The concentrate produced from the Forrestania project is characterised by low impurities such as magnesium which makes it more desirable to smelters.

The concentrator consists of a three-stage crushing circuit, followed by a single closed-circuit ball mill and a system of flotation tanks and thickening/filtration system.

The recovery rates for Cosmic Boy currently average between 85% and 90%. The recovery rates refer to the percentage amount of nickel recovered from the raw ore during processing.

At CBC a Mill Recovery Enhancement Project (MREP) has recently been commissioned. The MREP incorporates the use of the C ........